| Author (s): |
T.G. Costa, F.S. Miranda, M. Martini, M.R. Silva, B.P. Szpoganicz, C.P. Ianuzzi, V.V. Kozlova, B. Szpoganicz
|
| Title: |
EQUILIBRIUM STUDIES OF THE INTERACTIONS OF Zn(II) AND Cu(U) IONS WITH HUMIC ACID BY POTENTIOMETRIC TITRATION, IR AND FLUORESCENCE SPECTROSCOPY |
| Abstract: |
The interactions of Zn(II) and Cu(II) with humic acids (HA) were characterized by potentiometric titration, IR and fluorescence spectroscopy. The equilibrium constants determined were Log([Zn(Cat)]/[Zn+2][Cat]) = 15.25, Log([Zn(Cat),]/[ZnCat][Cat]) = 9.80, Log([Zn(Cat)(Sal)]/[Zn(Cat)][Sal]) = 8.59, Log([Zn(Cat)(Pht)]/[Zn(Cat)][Pht]) = 3.71, Log([Zn(OH)(Cat)2][H+]/[Zn(Cat),]) = -8.91, for the Zn(II) system, and Log([Cu(Cat)]/[Cu][Cat]) = 18.45, Log([Cu(Cat)2]l[CuCat][Cat]) = 14.18, and Log([Cu(Cat)(Sal)]/[Cu(Cat)][Sal]) = 8.44 for the Cu(Il) system The amounts of each group detected by potentiometric titration were: phenol = 0.666, carboxylic = 1.042, catechol = 0.540, phtalic = 1.163, and Salicylic= 0.810 mrnoles per gram of HA, and the speciation curves were calculated.
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| Keywords: |
Humic Acid, Zn(II), Cu(II), Speciation, Potentiometric Titration..
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| Year: |
2008
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| Initial page: |
1
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| Final page: |
10
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| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v17.n17.2008.4_2008.pdf |
|
|
| Author (s): |
Neeraj Kumar Fuloria, Vijender Singh, M. Shaharyar and Mohd. Ali
|
| Title: |
SYNTHESIS AND ANTIMICROBIAL STUDIES OF NOVEL IMINES AND OXADIAZOLES |
| Abstract: |
N-benzylidene-2-(4-chloro-3-methylphenoxy)acetohydrazides (3a-e), obtained by arylation of 2-(4-chloro-3-methyl phenoxy)acetohydrazide (2), was cyclized with acetic anhydride to yield 1-(5-(( 4-chloro-3-methylphenoxy)methyl)-2-phenyl-l ,3,4-oxadiazol- 3(2H)-yl)ethanones (4a-e). All the newly synthesized compounds were analytically and spectrally characterized and evaluated for anti-bacterial and anti-fungal activities.
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| Keywords: |
Acetohydrazide, aryloxy acetate, imines, oxadiazoles, antimicrobial activity.
|
| Year: |
2008
|
| Initial page: |
11
|
| Final page: |
22
|
| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v17.n17.2008.14_2008.pdf |
|
|
| Author (s): |
Awni Khatib, Fatbi Aqrn, David Deamer and Allen Oliver
|
| Title: |
[BIS(D-ALANINATO)DIAQUA)NICKEL(II) DIHYDRATE: PREPARATION AND CRYSTAL STRUCTURE |
| Abstract: |
The title complex of formula [Ni(NH2CH3CHCOO)2(H20)2].2H2O has been prepared from nickel(II) chloride in an aqueous solution by adding D-alanine and potassium hydroxide. It has beett crystallized from an aqueous solution and its structure was determined by X-ray structure analysis. The nickel(II) atom adopts distorted octahedral coordination geometry with two bidentate alanine molecules and two water molecules. The complex is neutral and dihydrated. The network crystal structure shows hydrogen bonding between water and amide hydrogens within the lattice, and each fragment of the complex contains two water molecules as hydrated water.
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| Keywords: |
Alanine Complex, Crystal Structure, Hydrogen Bonding, Water of Hydration.
|
| Year: |
2008
|
| Initial page: |
23
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| Final page: |
39
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| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v17.n17.2008.26_2008.pdf |
|
|
| Author (s): |
Lavinel G. Ionescu, Vera Lucia Trindade and Elizabeth Fatima de Souza
|
| Title: |
MICELLAR CATALYZED REACTION IN AQUEOUS GLYCEROL SOLUTIONS AND THE INTERNAL PRESSURE OF THE MEDIUM |
| Abstract: |
The experimental results obtained/or the hydrolysis of p-nitrophenyl diphenyl phosphate (NPDPP) in the presence of sodium hydroxide (NaOH), micelles of cetyltrimethylammonium bromide (CTAB), and an aqueous solution of glycerol were analyzed taking into consideration the internal pressure and the cohesive forces of the reaction medium. The effect of glycerol on mice/le formation and also its influence on the internal pressure of the reaction medium are large enough to affect the micellar catalyzed alkaline hydrolysis of the phosphate ester.
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| Keywords: |
Micellar Catalysis, Cetyltrimethylammonium Bromide (CTAB), Phosphate Esters, Solvent Effects, Internal Pressure of Liquids, Cohesive Forces, Glycerol.
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| Year: |
2008
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| Initial page: |
41
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| Final page: |
57
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| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v17.n17.2008.43_2008.pdf |
|
|
| Author (s): |
Paulo Cesar Pereira das Neves and Lavinel G. Ionescu
|
| Title: |
THE PERIODIC TABLE OF THE ELEMENTS AND THE ASSOCIATED MINERALS: URANIUM |
| Abstract: |
Uranium is silvery-white metal of the actinide series. It is the heaviest of naturally occurring elements and it is found in low concentrations in soil, water and rocks. Uranium is relatively reactive and combines with oxygen, sulfur, chlorine, fluorine, phosphorus, bromine and other elements. This article describes some of the properties and uses of uranium and presents a synopsis of the two hundred and four (204) uranium minerals known at the present time.
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| Keywords: |
Uranium, Mineralogy of Uranium, Properties of Uranium, Uses of Uranium.
|
| Year: |
2008
|
| Initial page: |
59
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| Final page: |
82
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| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v17.n17.2008.60_2008.pdf |
|
|
| Author (s): |
Lavinel G. Ionescu
|
| Title: |
BOOK REVIEW Introdução a Mineralogia Pratica |
| Abstract: |
PAULO CESAR PEREIRA DAS NEVES, FLÁVIA SCHENATO, FLÁVIO ANTÔNIO BACHI, "Introdução a Mineralogia Pratica", 2a edição, Revisada e Atualizada, Editora da ULBRA, Canoas, RS, Brasil, 2008, 335 paginas. A 2ª edição deste excelente livro apresenta além de um acréscimo no número de páginas, uma melhoria significativa com respeito à 1ª edição. Ver a nossa resenha original (South. Braz. J.Chem.,Vol.11, No.12, 21-22, 2003). O conteúdo científico e a qualidade gráfica, especialmente das imagens das espécies de minerais, podem ser considerados de primeira categoria. Os autores estao de parabens.
|
| Keywords: |
book review, mineralogy, geology.
|
| Year: |
2008
|
| Initial page: |
83
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| Final page: |
86
|
| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v17.n17.2008.84_2008.pdf |
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